chk.c revision 1.65
1 /* $NetBSD: chk.c,v 1.65 2023/12/03 18:17:41 rillig Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved. 5 * Copyright (c) 1994, 1995 Jochen Pohl 6 * All Rights Reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Jochen Pohl for 19 * The NetBSD Project. 20 * 4. The name of the author may not be used to endorse or promote products 21 * derived from this software without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 #if HAVE_NBTOOL_CONFIG_H 36 #include "nbtool_config.h" 37 #endif 38 39 #include <sys/cdefs.h> 40 #if defined(__RCSID) 41 __RCSID("$NetBSD: chk.c,v 1.65 2023/12/03 18:17:41 rillig Exp $"); 42 #endif 43 44 #include <ctype.h> 45 #include <limits.h> 46 #include <stdlib.h> 47 #include <string.h> 48 49 #include "lint2.h" 50 51 static void check_used_not_defined(const hte_t *); 52 static void check_defined_not_used(const hte_t *); 53 static void check_declared_not_used_or_defined(const hte_t *); 54 static void check_multiple_definitions(const hte_t *); 55 static void chkvtui(const hte_t *, sym_t *, sym_t *); 56 static void chkvtdi(const hte_t *, sym_t *, sym_t *); 57 static void chkfaui(const hte_t *, sym_t *, sym_t *); 58 static void chkau(const hte_t *, int, sym_t *, sym_t *, pos_t *, 59 fcall_t *, fcall_t *, type_t *, type_t *); 60 static void check_return_values(const hte_t *, sym_t *); 61 static void check_argument_declarations(const hte_t *, sym_t *, sym_t *); 62 static void printflike(const hte_t *, fcall_t *, int, const char *, type_t **); 63 static void scanflike(const hte_t *, fcall_t *, int, const char *, type_t **); 64 static void bad_format_string(const hte_t *, fcall_t *); 65 static void inconsistent_arguments(const hte_t *, fcall_t *, int); 66 static void too_few_arguments(const hte_t *, fcall_t *); 67 static void too_many_arguments(const hte_t *, fcall_t *); 68 static bool types_compatible(type_t *, type_t *, bool, bool, bool, bool *); 69 static bool prototypes_compatible(type_t *, type_t *, bool *); 70 static bool matches_no_arg_function(type_t *, bool *); 71 72 73 /* 74 * If there is a symbol named "main", mark it as used. 75 */ 76 void 77 mark_main_as_used(void) 78 { 79 hte_t *hte; 80 81 if ((hte = htab_search("main", false)) != NULL) 82 hte->h_used = true; 83 } 84 85 /* 86 * Performs all tests for a single name 87 */ 88 void 89 check_name(const hte_t *hte) 90 { 91 sym_t *sym, *def, *pdecl, *decl; 92 93 if (!uflag) { 94 check_used_not_defined(hte); 95 check_defined_not_used(hte); 96 if (xflag) 97 check_declared_not_used_or_defined(hte); 98 } 99 check_multiple_definitions(hte); 100 101 /* Get definition, prototype declaration and declaration */ 102 def = pdecl = decl = NULL; 103 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 104 if (def == NULL && (sym->s_def == DEF || sym->s_def == TDEF)) 105 def = sym; 106 if (pdecl == NULL && sym->s_def == DECL && 107 TP(sym->s_type)->t_tspec == FUNC && 108 TP(sym->s_type)->t_proto) { 109 pdecl = sym; 110 } 111 if (decl == NULL && sym->s_def == DECL) 112 decl = sym; 113 } 114 115 /* A prototype is better than an old-style declaration. */ 116 if (pdecl != NULL) 117 decl = pdecl; 118 119 chkvtui(hte, def, decl); 120 121 chkvtdi(hte, def, decl); 122 123 chkfaui(hte, def, decl); 124 125 check_return_values(hte, def); 126 127 check_argument_declarations(hte, def, decl); 128 } 129 130 /* 131 * Print a warning if the name has been used, but not defined. 132 */ 133 static void 134 check_used_not_defined(const hte_t *hte) 135 { 136 fcall_t *fcall; 137 usym_t *usym; 138 139 if (!hte->h_used || hte->h_def) 140 return; 141 142 if ((fcall = hte->h_calls) != NULL) { 143 /* %s used( %s ), but not defined */ 144 msg(0, hte->h_name, mkpos(&fcall->f_pos)); 145 } else if ((usym = hte->h_usyms) != NULL) { 146 /* %s used( %s ), but not defined */ 147 msg(0, hte->h_name, mkpos(&usym->u_pos)); 148 } 149 } 150 151 /* 152 * Print a warning if the name has been defined, but never used. 153 */ 154 static void 155 check_defined_not_used(const hte_t *hte) 156 { 157 sym_t *sym; 158 159 if (!hte->h_def || hte->h_used) 160 return; 161 162 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 163 if (sym->s_def == DEF || sym->s_def == TDEF) { 164 /* %s defined( %s ), but never used */ 165 msg(1, hte->h_name, mkpos(&sym->s_pos)); 166 break; 167 } 168 } 169 } 170 171 /* 172 * Print a warning if the variable has been declared, but is not used 173 * or defined. 174 */ 175 static void 176 check_declared_not_used_or_defined(const hte_t *hte) 177 { 178 sym_t *sym; 179 180 if (hte->h_syms == NULL || hte->h_used || hte->h_def) 181 return; 182 183 sym = hte->h_syms; 184 if (TP(sym->s_type)->t_tspec == FUNC) 185 return; 186 187 if (sym->s_def != DECL) 188 errx(1, "internal error: check_declared_not_used_or_defined"); 189 /* %s declared( %s ), but never used or defined */ 190 msg(2, hte->h_name, mkpos(&sym->s_pos)); 191 } 192 193 /* 194 * Print a warning if there is more than one definition for 195 * this name. 196 */ 197 static void 198 check_multiple_definitions(const hte_t *hte) 199 { 200 sym_t *sym, *def1; 201 202 if (!hte->h_def) 203 return; 204 205 def1 = NULL; 206 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 207 /* 208 * C90 allows tentative definitions of the same name in only 209 * one compilation unit. 210 */ 211 if (sym->s_def != DEF && (!sflag || sym->s_def != TDEF)) 212 continue; 213 if (sym->s_inline) 214 continue; 215 if (def1 == NULL) { 216 def1 = sym; 217 continue; 218 } 219 /* %s multiply defined \t%s :: %s */ 220 msg(3, hte->h_name, mkpos(&def1->s_pos), mkpos(&sym->s_pos)); 221 } 222 } 223 224 /* 225 * Print a warning if the return value assumed for a function call 226 * differs from the return value of the function definition or 227 * function declaration. 228 * 229 * If no definition/declaration can be found, the assumed return values 230 * are always int. So there is no need to compare with another function 231 * call as it's done for function arguments. 232 */ 233 static void 234 chkvtui(const hte_t *hte, sym_t *def, sym_t *decl) 235 { 236 fcall_t *call; 237 type_t *tp1, *tp2; 238 bool dowarn, eq; 239 tspec_t t1; 240 241 if (hte->h_calls == NULL) 242 return; 243 244 if (def == NULL) 245 def = decl; 246 if (def == NULL) 247 return; 248 249 t1 = (tp1 = TP(def->s_type)->t_subt)->t_tspec; 250 for (call = hte->h_calls; call != NULL; call = call->f_next) { 251 tp2 = TP(call->f_type)->t_subt; 252 eq = types_compatible(tp1, tp2, 253 true, false, false, (dowarn = false, &dowarn)); 254 if (!call->f_rused) { 255 /* no return value used */ 256 if ((t1 == STRUCT || t1 == UNION) && !eq) { 257 /* 258 * If a function returns a struct or union it 259 * must be declared to return a struct or 260 * union, also if the return value is ignored. 261 * This is necessary because the caller must 262 * allocate stack space for the return value. 263 * If it does not, the return value would 264 * overwrite other data. 265 * 266 * XXX Following message may be confusing 267 * because it appears also if the return value 268 * was declared inconsistently. But this 269 * behavior matches pcc-based lint, so it is 270 * accepted for now. 271 */ 272 /* %s function value must be declared ... */ 273 msg(17, hte->h_name, 274 mkpos(&def->s_pos), mkpos(&call->f_pos)); 275 } 276 continue; 277 } 278 if (!eq || (sflag && dowarn)) { 279 /* %s value used inconsistently \t%s :: %s */ 280 msg(4, hte->h_name, 281 mkpos(&def->s_pos), mkpos(&call->f_pos)); 282 } 283 } 284 } 285 286 /* 287 * Print a warning if a definition/declaration does not match another 288 * definition/declaration of the same name. For functions, only the 289 * types of return values are tested. 290 */ 291 static void 292 chkvtdi(const hte_t *hte, sym_t *def, sym_t *decl) 293 { 294 sym_t *sym; 295 type_t *tp1, *tp2; 296 bool eq, dowarn; 297 298 if (def == NULL) 299 def = decl; 300 if (def == NULL) 301 return; 302 303 tp1 = TP(def->s_type); 304 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 305 type_t *xt1, *xt2; 306 if (sym == def) 307 continue; 308 tp2 = TP(sym->s_type); 309 dowarn = false; 310 if (tp1->t_tspec == FUNC && tp2->t_tspec == FUNC) { 311 eq = types_compatible(xt1 = tp1->t_subt, 312 xt2 = tp2->t_subt, true, false, false, &dowarn); 313 } else { 314 eq = types_compatible(xt1 = tp1, xt2 = tp2, 315 false, false, false, &dowarn); 316 } 317 if (!eq || (sflag && dowarn)) { 318 /* %s value declared inconsistently (%s != %s) \t... */ 319 msg(5, hte->h_name, type_name(xt1), type_name(xt2), 320 mkpos(&def->s_pos), mkpos(&sym->s_pos)); 321 } 322 } 323 } 324 325 /* 326 * Print a warning if a function is called with arguments which does 327 * not match the function definition, declaration or another call 328 * of the same function. 329 */ 330 static void 331 chkfaui(const hte_t *hte, sym_t *def, sym_t *decl) 332 { 333 type_t *tp1, *tp2, **ap1, **ap2; 334 pos_t *pos1p = NULL; 335 fcall_t *calls, *call, *call1; 336 int n, as; 337 arginf_t *ai; 338 339 if ((calls = hte->h_calls) == NULL) 340 return; 341 342 /* 343 * If we find a function definition, we use this for comparison, 344 * otherwise the first prototype we can find. If there is no definition 345 * or prototype declaration, the first function call is used. 346 */ 347 tp1 = NULL; 348 call1 = NULL; 349 if (def != NULL) { 350 if ((tp1 = TP(def->s_type))->t_tspec != FUNC) 351 return; 352 pos1p = &def->s_pos; 353 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 354 if ((tp1 = TP(decl->s_type))->t_tspec != FUNC) 355 return; 356 pos1p = &decl->s_pos; 357 } 358 if (tp1 == NULL) { 359 call1 = calls; 360 calls = calls->f_next; 361 if ((tp1 = TP(call1->f_type))->t_tspec != FUNC) 362 return; 363 pos1p = &call1->f_pos; 364 } 365 366 n = 1; 367 for (call = calls; call != NULL; call = call->f_next) { 368 if ((tp2 = TP(call->f_type))->t_tspec != FUNC) 369 continue; 370 ap1 = tp1->t_args; 371 ap2 = tp2->t_args; 372 n = 0; 373 while (*ap1 != NULL && *ap2 != NULL) { 374 if (def != NULL && def->s_check_only_first_args && 375 n >= def->s_check_num_args) 376 break; 377 n++; 378 chkau(hte, n, def, decl, pos1p, call1, call, 379 *ap1, *ap2); 380 ap1++; 381 ap2++; 382 } 383 if (*ap1 == *ap2) { 384 /* equal # of arguments */ 385 } else if (def != NULL && def->s_check_only_first_args && 386 n >= def->s_check_num_args) { 387 /* 388 * function definition with VARARGS; The # of arguments 389 * of the call must be at least as large as the 390 * parameter of VARARGS. 391 */ 392 } else if (*ap2 != NULL && tp1->t_proto && tp1->t_vararg) { 393 /* 394 * prototype with ... and function call with at least 395 * the same # of arguments as declared in the 396 * prototype. 397 */ 398 } else { 399 /* %s: variable # of args \t%s :: %s */ 400 msg(7, hte->h_name, mkpos(pos1p), mkpos(&call->f_pos)); 401 continue; 402 } 403 404 /* perform SCANFLIKE/PRINTFLIKE tests */ 405 if (def == NULL || (!def->s_printflike && !def->s_scanflike)) 406 continue; 407 as = def->s_printflike 408 ? def->s_printflike_arg 409 : def->s_scanflike_arg; 410 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 411 if (ai->a_num == as) 412 break; 413 } 414 if (ai == NULL || !ai->a_fmt) 415 continue; 416 if (def->s_printflike) { 417 printflike(hte, call, n, ai->a_fstrg, ap2); 418 } else { 419 scanflike(hte, call, n, ai->a_fstrg, ap2); 420 } 421 } 422 } 423 424 /* 425 * Check a single argument in a function call. 426 * 427 * hte a pointer to the hash table entry of the function 428 * n the number of the argument (1..) 429 * def the function definition or NULL 430 * decl prototype declaration, old-style declaration or NULL 431 * pos1p position of definition, declaration of first call 432 * call1 first call, if both def and decl are old-style def/decl 433 * call checked call 434 * arg1 currently checked argument of def/decl/call1 435 * arg2 currently checked argument of call 436 * 437 */ 438 static void 439 chkau(const hte_t *hte, int n, sym_t *def, sym_t *decl, pos_t *pos1p, 440 fcall_t *call1, fcall_t *call, type_t *arg1, type_t *arg2) 441 { 442 bool promote, asgn, dowarn; 443 tspec_t t1, t2; 444 arginf_t *ai, *ai1; 445 446 /* 447 * If a function definition is available (def != NULL), we compare the 448 * function call (call) with the definition. Otherwise, if a function 449 * definition is available and it is not an old-style definition (decl 450 * != NULL && TP(decl->s_type)->t_proto), we compare the call with this 451 * declaration. Otherwise we compare it with the first call we have 452 * found (call1). 453 */ 454 455 /* arg1 must be promoted if it stems from an old-style definition */ 456 promote = def != NULL && def->s_old_style_function; 457 458 /* 459 * If we compare with a definition or declaration, we must perform the 460 * same checks for qualifiers in indirected types as in assignments. 461 */ 462 asgn = def != NULL || (decl != NULL && TP(decl->s_type)->t_proto); 463 464 dowarn = false; 465 if (types_compatible(arg1, arg2, true, promote, asgn, &dowarn) && 466 (!sflag || !dowarn)) 467 return; 468 469 /*- 470 * Other lint implementations print warnings as soon as the type of an 471 * argument does not match exactly the expected type. The result are 472 * lots of warnings which are really not necessary. 473 * We print a warning only if 474 * (0) at least one type is not an integer type and types differ 475 * (1) hflag is set and types differ 476 * (2) types differ, except in signedness 477 * 478 * If the argument is an integer constant whose msb is not set, 479 * signedness is ignored (e.g. 0 matches both signed and unsigned int). 480 * This is with and without hflag. 481 * 482 * If the argument is an integer constant with value 0 and the expected 483 * argument is of type pointer and the width of the integer constant is 484 * the same as the width of the pointer, no warning is printed. 485 */ 486 t1 = arg1->t_tspec; 487 t2 = arg2->t_tspec; 488 if (is_integer(t1) && is_integer(t2) && 489 !arg1->t_is_enum && !arg2->t_is_enum) { 490 if (promote) { 491 /* 492 * XXX Here is a problem: Although it is possible to 493 * pass an int where a char/short it expected, there 494 * may be loss in significant digits. We should first 495 * check for const arguments if they can be converted 496 * into the original parameter type. 497 */ 498 if (t1 == FLOAT) { 499 t1 = DOUBLE; 500 } else if (t1 == CHAR || t1 == SCHAR) { 501 t1 = INT; 502 } else if (t1 == UCHAR) { 503 t1 = tflag ? UINT : INT; 504 } else if (t1 == SHORT) { 505 t1 = INT; 506 } else if (t1 == USHORT) { 507 /* CONSTCOND */ 508 t1 = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 509 } 510 } 511 512 if (signed_type(t1) == signed_type(t2)) { 513 514 /* 515 * types differ only in signedness; get information 516 * about arguments 517 */ 518 519 /* 520 * treat a definition like a call with variable 521 * arguments 522 */ 523 ai1 = call1 != NULL ? call1->f_args : NULL; 524 525 /* 526 * if two calls are compared, ai1 is set to the 527 * information for the n-th argument, if this was a 528 * constant, otherwise to NULL 529 */ 530 for ( ; ai1 != NULL; ai1 = ai1->a_next) { 531 if (ai1->a_num == n) 532 break; 533 } 534 /* 535 * ai is set to the information of the n-th arg of the 536 * (second) call, if this was a constant, otherwise to 537 * NULL 538 */ 539 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 540 if (ai->a_num == n) 541 break; 542 } 543 544 if (ai1 == NULL && ai == NULL) { 545 /* no constant at all */ 546 if (!hflag) 547 return; 548 } else if (ai1 == NULL || ai == NULL) { 549 /* one constant */ 550 if (ai == NULL) 551 ai = ai1; 552 if (ai->a_zero || ai->a_pcon) 553 /* same value in signed and unsigned */ 554 return; 555 /* value (not representation) differently */ 556 } else { 557 /* 558 * two constants, one signed, one unsigned; if 559 * the msb of one of the constants is set, the 560 * argument is used inconsistently. 561 */ 562 if (!ai1->a_ncon && !ai->a_ncon) 563 return; 564 } 565 } 566 567 } else if (t1 == PTR && is_integer(t2)) { 568 for (ai = call->f_args; ai != NULL; ai = ai->a_next) { 569 if (ai->a_num == n) 570 break; 571 } 572 /* 573 * Vendor implementations of lint (e.g. HP-UX, Digital UNIX) 574 * don't care about the size of the integer argument, only 575 * whether or not it is zero. We do the same. 576 */ 577 if (ai != NULL && ai->a_zero) 578 return; 579 } 580 581 /* %s, arg %d used inconsistently \t%s[%s] :: %s[%s] */ 582 msg(6, hte->h_name, n, mkpos(pos1p), type_name(arg1), 583 mkpos(&call->f_pos), type_name(arg2)); 584 } 585 586 /* 587 * Compare the types in the NULL-terminated array ap with the format 588 * string fmt. 589 */ 590 static void 591 printflike(const hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 592 { 593 const char *fp; 594 char fc; 595 bool fwidth, prec, left, sign, space, alt, zero; 596 tspec_t sz, t1, t2 = NO_TSPEC; 597 type_t *tp; 598 599 fp = fmt; 600 fc = *fp++; 601 602 for (;;) { 603 if (fc == '\0') { 604 if (*ap != NULL) 605 too_many_arguments(hte, call); 606 break; 607 } 608 if (fc != '%') { 609 bad_format_string(hte, call); 610 break; 611 } 612 fc = *fp++; 613 fwidth = prec = left = sign = space = alt = zero = false; 614 sz = NO_TSPEC; 615 616 /* Flags */ 617 for (;;) { 618 if (fc == '-') { 619 if (left) 620 break; 621 left = true; 622 } else if (fc == '+') { 623 if (sign) 624 break; 625 sign = true; 626 } else if (fc == ' ') { 627 if (space) 628 break; 629 space = true; 630 } else if (fc == '#') { 631 if (alt) 632 break; 633 alt = true; 634 } else if (fc == '0') { 635 if (zero) 636 break; 637 zero = true; 638 } else { 639 break; 640 } 641 fc = *fp++; 642 } 643 644 /* field width */ 645 if (ch_isdigit(fc)) { 646 fwidth = true; 647 do { fc = *fp++; } while (ch_isdigit(fc)); 648 } else if (fc == '*') { 649 fwidth = true; 650 fc = *fp++; 651 if ((tp = *ap++) == NULL) { 652 too_few_arguments(hte, call); 653 break; 654 } 655 n++; 656 if ((t1 = tp->t_tspec) != INT && (hflag || t1 != UINT)) 657 inconsistent_arguments(hte, call, n); 658 } 659 660 /* precision */ 661 if (fc == '.') { 662 fc = *fp++; 663 prec = true; 664 if (ch_isdigit(fc)) { 665 do { fc = *fp++; } while (ch_isdigit(fc)); 666 } else if (fc == '*') { 667 fc = *fp++; 668 if ((tp = *ap++) == NULL) { 669 too_few_arguments(hte, call); 670 break; 671 } 672 n++; 673 if (tp->t_tspec != INT) 674 inconsistent_arguments(hte, call, n); 675 } else { 676 bad_format_string(hte, call); 677 break; 678 } 679 } 680 681 if (fc == 'h') { 682 sz = SHORT; 683 } else if (fc == 'l') { 684 sz = LONG; 685 } else if (fc == 'q') { 686 sz = LLONG; 687 } else if (fc == 'L') { 688 sz = LDOUBLE; 689 } 690 if (sz != NO_TSPEC) 691 fc = *fp++; 692 693 if (fc == '%') { 694 if (sz != NO_TSPEC || left || sign || space || 695 alt || zero || prec || fwidth) { 696 bad_format_string(hte, call); 697 } 698 fc = *fp++; 699 continue; 700 } 701 702 if (fc == '\0') { 703 bad_format_string(hte, call); 704 break; 705 } 706 707 if ((tp = *ap++) == NULL) { 708 too_few_arguments(hte, call); 709 break; 710 } 711 n++; 712 if ((t1 = tp->t_tspec) == PTR) 713 t2 = tp->t_subt->t_tspec; 714 715 if (fc == 'd' || fc == 'i') { 716 if (alt || sz == LDOUBLE) { 717 bad_format_string(hte, call); 718 break; 719 } 720 int_conv: 721 if (sz == LONG) { 722 if (t1 != LONG && (hflag || t1 != ULONG)) 723 inconsistent_arguments(hte, call, n); 724 } else if (sz == LLONG) { 725 if (t1 != LLONG && (hflag || t1 != ULLONG)) 726 inconsistent_arguments(hte, call, n); 727 } else { 728 /* 729 * SHORT is always promoted to INT, USHORT to 730 * INT or UINT. 731 */ 732 if (t1 != INT && (hflag || t1 != UINT)) 733 inconsistent_arguments(hte, call, n); 734 } 735 } else if (fc == 'o' || fc == 'u' || fc == 'x' || fc == 'X') { 736 if ((alt && fc == 'u') || sz == LDOUBLE) 737 bad_format_string(hte, call); 738 uint_conv: 739 if (sz == LONG) { 740 if (t1 != ULONG && (hflag || t1 != LONG)) 741 inconsistent_arguments(hte, call, n); 742 } else if (sz == LLONG) { 743 if (t1 != ULLONG && (hflag || t1 != LLONG)) 744 inconsistent_arguments(hte, call, n); 745 } else if (sz == SHORT) { 746 /* USHORT was promoted to INT or UINT */ 747 if (t1 != UINT && t1 != INT) 748 inconsistent_arguments(hte, call, n); 749 } else { 750 if (t1 != UINT && (hflag || t1 != INT)) 751 inconsistent_arguments(hte, call, n); 752 } 753 } else if (fc == 'D' || fc == 'O' || fc == 'U') { 754 if ((alt && fc != 'O') || sz != NO_TSPEC || !tflag) 755 bad_format_string(hte, call); 756 sz = LONG; 757 if (fc == 'D') { 758 goto int_conv; 759 } else { 760 goto uint_conv; 761 } 762 } else if (fc == 'f' || fc == 'e' || fc == 'E' || 763 fc == 'g' || fc == 'G') { 764 if (sz == NO_TSPEC) 765 sz = DOUBLE; 766 if (sz != DOUBLE && sz != LDOUBLE) 767 bad_format_string(hte, call); 768 if (t1 != sz) 769 inconsistent_arguments(hte, call, n); 770 } else if (fc == 'c') { 771 if (sz != NO_TSPEC || alt || zero) 772 bad_format_string(hte, call); 773 if (t1 != INT) 774 inconsistent_arguments(hte, call, n); 775 } else if (fc == 's') { 776 if (sz != NO_TSPEC || alt || zero) 777 bad_format_string(hte, call); 778 if (t1 != PTR || 779 (t2 != CHAR && t2 != UCHAR && t2 != SCHAR)) { 780 inconsistent_arguments(hte, call, n); 781 } 782 } else if (fc == 'p') { 783 if (fwidth || prec || sz != NO_TSPEC || alt || zero) 784 bad_format_string(hte, call); 785 if (t1 != PTR || (hflag && t2 != VOID)) 786 inconsistent_arguments(hte, call, n); 787 } else if (fc == 'n') { 788 if (fwidth || prec || alt || zero || sz == LDOUBLE) 789 bad_format_string(hte, call); 790 if (t1 != PTR) { 791 inconsistent_arguments(hte, call, n); 792 } else if (sz == LONG) { 793 if (t2 != LONG && t2 != ULONG) 794 inconsistent_arguments(hte, call, n); 795 } else if (sz == SHORT) { 796 if (t2 != SHORT && t2 != USHORT) 797 inconsistent_arguments(hte, call, n); 798 } else { 799 if (t2 != INT && t2 != UINT) 800 inconsistent_arguments(hte, call, n); 801 } 802 } else { 803 bad_format_string(hte, call); 804 break; 805 } 806 807 fc = *fp++; 808 } 809 } 810 811 /* 812 * Compare the types in the NULL-terminated array ap with the format 813 * string fmt. 814 */ 815 static void 816 scanflike(const hte_t *hte, fcall_t *call, int n, const char *fmt, type_t **ap) 817 { 818 const char *fp; 819 char fc; 820 bool noasgn, fwidth; 821 tspec_t sz, t1 = NO_TSPEC, t2 = NO_TSPEC; 822 type_t *tp = NULL; 823 824 fp = fmt; 825 fc = *fp++; 826 827 for (;;) { 828 if (fc == '\0') { 829 if (*ap != NULL) 830 too_many_arguments(hte, call); 831 break; 832 } 833 if (fc != '%') { 834 bad_format_string(hte, call); 835 break; 836 } 837 fc = *fp++; 838 839 noasgn = fwidth = false; 840 sz = NO_TSPEC; 841 842 if (fc == '*') { 843 noasgn = true; 844 fc = *fp++; 845 } 846 847 if (ch_isdigit(fc)) { 848 fwidth = true; 849 do { fc = *fp++; } while (ch_isdigit(fc)); 850 } 851 852 if (fc == 'h') { 853 sz = SHORT; 854 } else if (fc == 'l') { 855 sz = LONG; 856 } else if (fc == 'q') { 857 sz = LLONG; 858 } else if (fc == 'L') { 859 sz = LDOUBLE; 860 } 861 if (sz != NO_TSPEC) 862 fc = *fp++; 863 864 if (fc == '%') { 865 if (sz != NO_TSPEC || noasgn || fwidth) 866 bad_format_string(hte, call); 867 fc = *fp++; 868 continue; 869 } 870 871 if (!noasgn) { 872 if ((tp = *ap++) == NULL) { 873 too_few_arguments(hte, call); 874 break; 875 } 876 n++; 877 if ((t1 = tp->t_tspec) == PTR) 878 t2 = tp->t_subt->t_tspec; 879 } 880 881 if (fc == 'd' || fc == 'i' || fc == 'n') { 882 if (sz == LDOUBLE) 883 bad_format_string(hte, call); 884 if (sz != SHORT && sz != LONG && sz != LLONG) 885 sz = INT; 886 conv: 887 if (!noasgn) { 888 if (t1 != PTR) { 889 inconsistent_arguments(hte, call, n); 890 } else if (t2 != signed_type(sz)) { 891 inconsistent_arguments(hte, call, n); 892 } else if (hflag && t2 != sz) { 893 inconsistent_arguments(hte, call, n); 894 } else if (tp->t_subt->t_const) { 895 inconsistent_arguments(hte, call, n); 896 } 897 } 898 } else if (fc == 'o' || fc == 'u' || fc == 'x') { 899 if (sz == LDOUBLE) 900 bad_format_string(hte, call); 901 if (sz == SHORT) { 902 sz = USHORT; 903 } else if (sz == LONG) { 904 sz = ULONG; 905 } else if (sz == LLONG) { 906 sz = ULLONG; 907 } else { 908 sz = UINT; 909 } 910 goto conv; 911 } else if (fc == 'D') { 912 if (sz != NO_TSPEC || !tflag) 913 bad_format_string(hte, call); 914 sz = LONG; 915 goto conv; 916 } else if (fc == 'O') { 917 if (sz != NO_TSPEC || !tflag) 918 bad_format_string(hte, call); 919 sz = ULONG; 920 goto conv; 921 } else if (fc == 'X') { 922 /* 923 * XXX valid in C90, but in NetBSD's libc implemented 924 * as "lx". That's why it should be avoided. 925 */ 926 if (sz != NO_TSPEC || !tflag) 927 bad_format_string(hte, call); 928 sz = ULONG; 929 goto conv; 930 } else if (fc == 'E') { 931 /* 932 * XXX valid in C90, but in NetBSD's libc implemented 933 * as "lf". That's why it should be avoided. 934 */ 935 if (sz != NO_TSPEC || !tflag) 936 bad_format_string(hte, call); 937 sz = DOUBLE; 938 goto conv; 939 } else if (fc == 'F') { 940 /* XXX only for backward compatibility */ 941 if (sz != NO_TSPEC || !tflag) 942 bad_format_string(hte, call); 943 sz = DOUBLE; 944 goto conv; 945 } else if (fc == 'G') { 946 /* 947 * XXX valid in C90, but in NetBSD's libc not 948 * implemented 949 */ 950 if (sz != NO_TSPEC && sz != LONG && sz != LDOUBLE) 951 bad_format_string(hte, call); 952 goto fconv; 953 } else if (fc == 'e' || fc == 'f' || fc == 'g') { 954 fconv: 955 if (sz == NO_TSPEC) { 956 sz = FLOAT; 957 } else if (sz == LONG) { 958 sz = DOUBLE; 959 } else if (sz != LDOUBLE) { 960 bad_format_string(hte, call); 961 sz = FLOAT; 962 } 963 goto conv; 964 } else if (fc == 's' || fc == '[' || fc == 'c') { 965 if (sz != NO_TSPEC) 966 bad_format_string(hte, call); 967 if (fc == '[') { 968 if ((fc = *fp++) == '-') { 969 bad_format_string(hte, call); 970 fc = *fp++; 971 } 972 if (fc != ']') { 973 bad_format_string(hte, call); 974 if (fc == '\0') 975 break; 976 } 977 } 978 if (!noasgn) { 979 if (t1 != PTR) { 980 inconsistent_arguments(hte, call, n); 981 } else if (t2 != CHAR && t2 != UCHAR && 982 t2 != SCHAR) { 983 inconsistent_arguments(hte, call, n); 984 } 985 } 986 } else if (fc == 'p') { 987 if (sz != NO_TSPEC) 988 bad_format_string(hte, call); 989 if (!noasgn) { 990 if (t1 != PTR || t2 != PTR) { 991 inconsistent_arguments(hte, call, n); 992 } else if (tp->t_subt->t_subt->t_tspec!=VOID) { 993 if (hflag) 994 inconsistent_arguments(hte, call, n); 995 } 996 } 997 } else { 998 bad_format_string(hte, call); 999 break; 1000 } 1001 1002 fc = *fp++; 1003 } 1004 } 1005 1006 static void 1007 bad_format_string(const hte_t *hte, fcall_t *call) 1008 { 1009 1010 /* %s: malformed format string \t%s */ 1011 msg(13, hte->h_name, mkpos(&call->f_pos)); 1012 } 1013 1014 static void 1015 inconsistent_arguments(const hte_t *hte, fcall_t *call, int n) 1016 { 1017 1018 /* %s, arg %d inconsistent with format \t%s */ 1019 msg(14, hte->h_name, n, mkpos(&call->f_pos)); 1020 } 1021 1022 static void 1023 too_few_arguments(const hte_t *hte, fcall_t *call) 1024 { 1025 1026 /* %s: too few args for format \t%s */ 1027 msg(15, hte->h_name, mkpos(&call->f_pos)); 1028 } 1029 1030 static void 1031 too_many_arguments(const hte_t *hte, fcall_t *call) 1032 { 1033 1034 /* %s: too many args for format \t%s */ 1035 msg(16, hte->h_name, mkpos(&call->f_pos)); 1036 } 1037 1038 /* 1039 * List of functions where we usually don't care about their result. 1040 * NB: Must be sorted. 1041 */ 1042 static const char ignorelist[][8] = { 1043 "memcpy", 1044 "memmove", 1045 "memset", 1046 "printf", 1047 "strcat", 1048 "strcpy", 1049 "vprintf", 1050 }; 1051 1052 /* 1053 * Print warnings for return values which are used but not returned, 1054 * or return values which are always or sometimes ignored. 1055 */ 1056 static void 1057 check_return_values(const hte_t *hte, sym_t *def) 1058 { 1059 fcall_t *call; 1060 bool used, ignored; 1061 1062 if (def == NULL) 1063 /* don't know whether or not the functions returns a value */ 1064 return; 1065 1066 if (hte->h_calls == NULL) 1067 return; 1068 1069 if (def->s_function_has_return_value) { 1070 /* 1071 * XXX as soon as we are able to disable single warnings, the 1072 * following dependencies from hflag should be removed. But for 1073 * now I don't want to be bothered by these warnings which are 1074 * almost always useless. 1075 */ 1076 if (!hflag) 1077 return; 1078 if (hflag && bsearch(hte->h_name, ignorelist, 1079 sizeof(ignorelist) / sizeof(ignorelist[0]), 1080 sizeof(ignorelist[0]), 1081 (int (*)(const void *, const void *))strcmp) != NULL) 1082 return; 1083 1084 /* function has return value */ 1085 used = ignored = false; 1086 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1087 used |= call->f_rused || call->f_rdisc; 1088 ignored |= !call->f_rused && !call->f_rdisc; 1089 } 1090 if (!used && ignored) { 1091 /* %s returns value which is always ignored */ 1092 msg(8, hte->h_name); 1093 } else if (used && ignored) { 1094 /* %s returns value which is sometimes ignored */ 1095 msg(9, hte->h_name); 1096 } 1097 } else { 1098 /* function has no return value */ 1099 for (call = hte->h_calls; call != NULL; call = call->f_next) { 1100 if (call->f_rused) 1101 /* %s value is used( %s ), but none returned */ 1102 msg(10, hte->h_name, mkpos(&call->f_pos)); 1103 } 1104 } 1105 } 1106 1107 /* 1108 * Print warnings for inconsistent argument declarations. 1109 */ 1110 static void 1111 check_argument_declarations(const hte_t *hte, sym_t *def, sym_t *decl) 1112 { 1113 bool osdef, eq, dowarn; 1114 int n; 1115 sym_t *sym1, *sym; 1116 type_t **ap1, **ap2, *tp1, *tp2; 1117 1118 osdef = false; 1119 if (def != NULL) { 1120 osdef = def->s_old_style_function; 1121 sym1 = def; 1122 } else if (decl != NULL && TP(decl->s_type)->t_proto) { 1123 sym1 = decl; 1124 } else { 1125 return; 1126 } 1127 if (TP(sym1->s_type)->t_tspec != FUNC) 1128 return; 1129 1130 /* 1131 * XXX Prototypes should also be compared with old-style function 1132 * declarations. 1133 */ 1134 1135 for (sym = hte->h_syms; sym != NULL; sym = sym->s_next) { 1136 if (sym == sym1 || !TP(sym->s_type)->t_proto) 1137 continue; 1138 ap1 = TP(sym1->s_type)->t_args; 1139 ap2 = TP(sym->s_type)->t_args; 1140 n = 0; 1141 while (*ap1 != NULL && *ap2 != NULL) { 1142 type_t *xt1, *xt2; 1143 dowarn = false; 1144 eq = types_compatible(xt1 = *ap1, xt2 = *ap2, 1145 true, osdef, false, &dowarn); 1146 if (!eq || dowarn) { 1147 /* %s, arg %d declared inconsistently ... */ 1148 msg(11, hte->h_name, n + 1, 1149 type_name(xt1), type_name(xt2), 1150 mkpos(&sym1->s_pos), mkpos(&sym->s_pos)); 1151 } 1152 n++; 1153 ap1++; 1154 ap2++; 1155 } 1156 if (*ap1 == *ap2) { 1157 tp1 = TP(sym1->s_type); 1158 tp2 = TP(sym->s_type); 1159 if (tp1->t_vararg == tp2->t_vararg) 1160 continue; 1161 if (tp2->t_vararg && sym1->s_check_only_first_args && 1162 sym1->s_check_num_args == n && !sflag) { 1163 continue; 1164 } 1165 } 1166 /* %s: variable # of args declared \t%s :: %s */ 1167 msg(12, hte->h_name, mkpos(&sym1->s_pos), mkpos(&sym->s_pos)); 1168 } 1169 } 1170 1171 1172 /* 1173 * Check compatibility of two types. Returns whether types are compatible. 1174 * 1175 * ignqual if set, ignore qualifiers of outermost type; used for 1176 * function arguments 1177 * promote if set, promote left type before comparison; used for 1178 * comparisons of arguments with parameters of old-style 1179 * definitions 1180 * asgn left indirected type must have at least the same qualifiers 1181 * like right indirected type (for assignments and function 1182 * arguments) 1183 * *dowarn set to true if an old-style declaration was compared with 1184 * an incompatible prototype declaration 1185 */ 1186 static bool 1187 types_compatible(type_t *tp1, type_t *tp2, 1188 bool ignqual, bool promot, bool asgn, bool *dowarn) 1189 { 1190 tspec_t t, to; 1191 int indir; 1192 1193 to = NO_TSPEC; 1194 indir = 0; 1195 1196 while (tp1 != NULL && tp2 != NULL) { 1197 1198 t = tp1->t_tspec; 1199 if (promot) { 1200 if (t == FLOAT) { 1201 t = DOUBLE; 1202 } else if (t == CHAR || t == SCHAR) { 1203 t = INT; 1204 } else if (t == UCHAR) { 1205 t = tflag ? UINT : INT; 1206 } else if (t == SHORT) { 1207 t = INT; 1208 } else if (t == USHORT) { 1209 /* CONSTCOND */ 1210 t = INT_MAX < USHRT_MAX || tflag ? UINT : INT; 1211 } 1212 } 1213 1214 if (asgn && to == PTR) { 1215 if (indir == 1 && (t == VOID || tp2->t_tspec == VOID)) 1216 return true; 1217 } 1218 1219 if (t != tp2->t_tspec) { 1220 /* 1221 * Give pointer to types which differ only in 1222 * signedness a chance if not sflag and not hflag. 1223 */ 1224 if (sflag || hflag || to != PTR) 1225 return false; 1226 if (signed_type(t) != signed_type(tp2->t_tspec)) 1227 return false; 1228 } 1229 1230 if (tp1->t_is_enum && tp2->t_is_enum) { 1231 if (tp1->t_istag && tp2->t_istag) { 1232 return tp1->t_tag == tp2->t_tag; 1233 } else if (tp1->t_istynam && tp2->t_istynam) { 1234 return tp1->t_tynam == tp2->t_tynam; 1235 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1236 return (tp1->t_uniqpos.p_line == 1237 tp2->t_uniqpos.p_line && 1238 tp1->t_uniqpos.p_file == 1239 tp2->t_uniqpos.p_file && 1240 tp1->t_uniqpos.p_uniq == 1241 tp2->t_uniqpos.p_uniq); 1242 } else { 1243 return false; 1244 } 1245 } 1246 1247 /* 1248 * XXX Handle combinations of enum and int if eflag is set. But 1249 * note: enum and 0 should be allowed. 1250 */ 1251 1252 if (asgn && indir == 1) { 1253 if (!tp1->t_const && tp2->t_const) 1254 return false; 1255 if (!tp1->t_volatile && tp2->t_volatile) 1256 return false; 1257 } else if (!ignqual && !tflag) { 1258 if (tp1->t_const != tp2->t_const) 1259 return false; 1260 if (tp1->t_const != tp2->t_const) 1261 return false; 1262 } 1263 1264 if (t == STRUCT || t == UNION) { 1265 if (tp1->t_istag && tp2->t_istag) { 1266 return tp1->t_tag == tp2->t_tag; 1267 } else if (tp1->t_istynam && tp2->t_istynam) { 1268 return tp1->t_tynam == tp2->t_tynam; 1269 } else if (tp1->t_isuniqpos && tp2->t_isuniqpos) { 1270 return (tp1->t_uniqpos.p_line == 1271 tp2->t_uniqpos.p_line && 1272 tp1->t_uniqpos.p_file == 1273 tp2->t_uniqpos.p_file && 1274 tp1->t_uniqpos.p_uniq == 1275 tp2->t_uniqpos.p_uniq); 1276 } else { 1277 return false; 1278 } 1279 } 1280 1281 if (t == ARRAY && tp1->t_dim != tp2->t_dim) { 1282 if (tp1->t_dim != 0 && tp2->t_dim != 0) 1283 return false; 1284 } 1285 1286 if (t == FUNC) { 1287 if (tp1->t_proto && tp2->t_proto) { 1288 if (!prototypes_compatible(tp1, tp2, dowarn)) 1289 return false; 1290 } else if (tp1->t_proto) { 1291 if (!matches_no_arg_function(tp1, dowarn)) 1292 return false; 1293 } else if (tp2->t_proto) { 1294 if (!matches_no_arg_function(tp2, dowarn)) 1295 return false; 1296 } 1297 } 1298 1299 tp1 = tp1->t_subt; 1300 tp2 = tp2->t_subt; 1301 ignqual = promot = false; 1302 to = t; 1303 indir++; 1304 } 1305 1306 return tp1 == tp2; 1307 } 1308 1309 /* 1310 * Compares arguments of two prototypes 1311 */ 1312 static bool 1313 prototypes_compatible(type_t *tp1, type_t *tp2, bool *dowarn) 1314 { 1315 type_t **a1, **a2; 1316 1317 if (tp1->t_vararg != tp2->t_vararg) 1318 return false; 1319 1320 a1 = tp1->t_args; 1321 a2 = tp2->t_args; 1322 1323 while (*a1 != NULL && *a2 != NULL) { 1324 1325 if (!types_compatible(*a1, *a2, true, false, false, dowarn)) 1326 return false; 1327 1328 a1++; 1329 a2++; 1330 } 1331 1332 return *a1 == *a2; 1333 } 1334 1335 /* 1336 * Returns whether all parameters of a prototype are compatible with an 1337 * old-style function declaration. 1338 * 1339 * This is the case if the following conditions are met: 1340 * 1. the prototype must have a fixed number of parameters 1341 * 2. no parameter is of type float 1342 * 3. no parameter is converted to another type if integer promotion 1343 * is applied on it 1344 */ 1345 static bool 1346 matches_no_arg_function(type_t *tp, bool *dowarn) 1347 { 1348 type_t **arg; 1349 tspec_t t; 1350 1351 if (tp->t_vararg && dowarn != NULL) 1352 *dowarn = true; 1353 for (arg = tp->t_args; *arg != NULL; arg++) { 1354 if ((t = (*arg)->t_tspec) == FLOAT) 1355 return false; 1356 if (t == CHAR || t == SCHAR || t == UCHAR) 1357 return false; 1358 if (t == SHORT || t == USHORT) 1359 return false; 1360 } 1361 return true; 1362 } 1363
Indexes created Tue Oct 14 21:09:58 GMT 2025